399740 has 48 divisors (see below), whose sum is σ = 967680. Its totient is φ = 137280.

The previous prime is 399739. The next prime is 399757. The reversal of 399740 is 47993.

It is a happy number.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 399697 and 399706.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 399740.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5021 + ... + 5099.

It is an arithmetic number, because the mean of its divisors is an integer number (20160).

2³⁹⁹⁷⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (483840).

399740 is an abundant number, since it is smaller than the sum of its proper divisors (567940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399740 is a wasteful number, since it uses less digits than its factorization.

399740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 32.

The square root of 399740 is about 632.2499505733. The cubic root of 399740 is about 73.6646623762.

It can be divided in two parts, 39 and 9740, that added together give a palindrome (9779).

The spelling of 399740 in words is "three hundred ninety-nine thousand, seven hundred forty".